POSEIDON, quick tour
Ernesto
21st September, 2018
Research Questions
- To NGOs:
- To academics:
- To other ABM practitioners:
- Contribute to general problems
Agent Based Models
- Define:
- Behaviour of the individual
- How they interact
- Generate
Agent-Based Models and their use
- Useful when
- Feedback agent-environment-regulations
- Heterogeneity (spatial, economic, etc..)
- Individual data is available
Poseidon
What do you need for POSEIDON?
- Coded in Java
- Skill
- Basic GUI
- Input modifications
- Algorithm modifications
- Data needs
- Conceptual model
- Flexibility tradeoff
- Confidence intervals vs data available
Decision Making is difficult
- The profit maximizing boat; decides:
- Where to fish
- Optimal path
- Number of trips per season
- State space is immense:
- Belief state of biomass available per fishing spot, per species, per time step
- Location and action of all competitors
- Bellman equation unsolvable
Pragmatism
- Logbook data
- Surveys
- “I have only 5 spots and cycle through them”
- “If in a bind, track highliner on radar and copy them”
- “Explore a fixed proportion of tows”
- “Draw peaks and valleys on maps”
Zoo approach
- Collect decision algorithms
- From interviews
- From CS-literature
- Implement them in the same agent-based model
- Test strengths/weaknesses in theory
- Compare to real data
- Use it for policy suggestions and sensitivity analysis
Explore-Exploit-Imitate
\begin{algorithm}
\caption{Explore-Exploit-Imitate}
\begin{algorithmic}
\WHILE{game is not over}
\IF{$\text{random} < \epsilon$}
\COMMENT{with probability $\epsilon$, explore}
\STATE $\hat \delta \sim U[-\delta,\delta]$
\STATE $\text{position} \leftarrow \text{position} + \hat \delta$
\COMMENT{explore by shocking your position by $\delta$}
\ELSE
\STATE $\text{profits}_f$ are the profits made by your most profitable friend
\STATE $\text{profits}_{\text{me}}$ are the profits just made by this agent
\IF{$\text{profits}_f>\text{profits}_{\text{me}}$}
\STATE copy friend location
\ELSE
\STATE stay at current location
\ENDIF
\ENDIF
\ENDWHILE
\end{algorithmic}
\end{algorithm}
Fishing the Australian line
